"The Islamic Republic of Iran is among the most important countries hosting millions of refugees and immigrants, specially Afghans, and has provided the necessary conditions for their settlement," Guterres said at a press conference in Turkmenistan on Sunday.
Noting that Iran at present is sheltering over one million Afghan refugees, he said that the country has also provided the necessary facilities for their living, education and health.
Guterres appreciated Iran for sheltering foreign refugees, and called on the international community to support Iran's efforts and use the country's experiences in this regard.
Earlier, the United Nations High Commission for Refugees (UNHCR) Representative in Iran Bernard Doyle had also lauded the country for its efforts and effective measures in supporting the Afghan refugees residing in Iran, and underlined that Tehran has shown a kind and humanitarian behavior towards the Afghan nationals.
"Iran has well fulfilled its humanitarian duties in this regard," Doyle said in a meeting with Iranian Foreign Minister Ali Akbar Salehi in 2011.
Over one million illegal Afghan refugees currently live in Iran but the Islamic Republic has received little international support.
Tehran has called on the international community to strengthen support for Iran's hosting of the Afghan refugees and support repatriation and rehabilitation of the refugees.
Voluntary repatriation of Afghan refugees from Iran has slowed in recent years in the face of poor security and economic conditions in Afghanistan, which Tehran blames on the US-led invasion of the country in 2001.
The Iranian government and the United Nations Refugee Agency have signed a contract with Alborz insurance company on giving all registered refugees in Iran access to health care and insurance.